If you want a device that just works, and you are happy living within apples restrictions which mostly are the apps, and then customizing things like icons background apps stuff like that. iPhone 5 is the place to be. If you like to customize your phone, tweak things, and be in a more open environment look at android. I work in IT and have an iphone, I have had one since the iphone 1 and I love it. I prefer for my phone to just work instead of having to tweak things on it.
Whilst you do make a good point, I think If it's just for work then a £700 phone is pointless
I think you misunderstood me, I did not mean it just for work, I ment that it just works, like doesn't have a lot of problems, requires much less tweaking than android, everytime I use an android device it seems something changes from an update somewhere and I have to change it back to the way I had it. With the iphone for the most part everything is in the same place and functions the same way no matter what application, or OS version you are running. I have not seen that on android.